Automatic supervisory equipment



May 1, 1934. J. H. OLIVER AUTOMATIC SUPERVISORY EQUIPMENT :5 Shets-Sheet 1 Filed Aug. 16, 1929 R R3 Nuk Inventoh: James H-.O l ive =E MQ kwiw 8% 53 H I8 Attorney.

May 1, 1934- J. H. OLIVER AUTOMATIC SUPERVISORY EQUIPMENT Filed Aug. 16, 1929 3 Sheets-Sheet 2 Inventor James H.Oliver-, y Mi v HisAttoPney AUTOMATI C SUPERVI SORY EQUIPMENT Filed Aug. 16, 1929 3 Sheets-Sheet 3 by HisAttohme y Fig.3.

Patented May 1, 1934 rate fiiTlET Fl'CE James H. Oliver, Philadelphia, Pa, assignor to General Electric Company, a corporation of New York Application August 18, 1929, Serial No. 386,429

Claims.

My invention relates to supervisory control systems and more particularly to novel methods and means whereby a remote apparatus unit, may be selectively controlled and supervised.

My invention has for one of its objects to provide a supervisory control system which has the characteristic of great reliability both in its selecting and remote control function and which may be employed to supervise and control important apparatus units of a power distribution system, for example, over lines which may parallel those of the distribution system itself and which are therefore subject to severe inductive disturbances.

In the remote control and supervision of apparatus units over lines of the character indicated the effect upon the control equipment of induced potentials in the line may be reduced by going to the trouble and expense of properly shielding the lEne conductors thereby to reduce the induced potential itself.

My invention has for one of its objects, however, to provide a system which will operate with great reliability over these lines independently of any shielding of the line conductors, insulating transformers or condensers which may be included in the line, and which further accomplishes this result without recourse to expensive high frequency carrier current equipment.

Another object of my invention is to provide certain novel improvements in the nature of the selecting equipment employed whereby increased reliability in the selecting operation may be had and whereby, due to such faulty operation of the selecting equipment as may occur from time to time, the operation will in practically all cases result in no selection, or whereby the possibility of an incorrect selection of a remote apparatus unit is rendered extremely remote.

A further object of the invention is to provide a novel method of control of remote equipment and means whereby the method may be practiced, including means, whereby, after a remote apparatus unit has been selected, as in response to a predetermined code, it may then be controlled only in response to a fixed additional code. accordancewith this feature of the invention after an apparatus unit has been selected in response to a certain code the apparatus unit, if it ,e a power switch, for example, will be operated to its closed position and in response to a different code will be operated to its open position. Further in accordance with this feature of my invention I provide means whereby when through the apparatus unit selecting equipment, a particular apparatus unit has been selected it may be successively operated and controlled in response to the additional codes from one position to another, back and forth, as many times as desired without again operating the apparatus unit selecting equipment. A further co object of the invention is to provide means whereby, when due to faulty operation of the equipment in response to these additional codes in practically all cases no control operation is effected and whereby the possibility of an incorrect control operation in response to these additional codes is rendered very remote.

A further object of the invention is to provide coding means common to all of the remote units supervised whereby after any unit has been selected a persistant indication of the unit selected and the position ther of may be transmitted from the remote station to the dispatchers station. Another object is to provide means whereby this result is eifected without operation of the selected unit and whereby when the unit is operated either automatically or by remote control the indication is altered in accordance with the new position of the unit.

A still further object of my invention relates 0 to certain improvements in meansfor indicating in the dispatchers station the automatic or accidental operation of remote units and the position thereof.

A. further object of the invention is to provide a system in which the equipment provided may be utilized for the remote control and supervision of apparatus units having three or more positions such as rheostats, water gates and the like, and whereby with the addition of a very slight amount of equipment both units having two positions and units having a greater number of positions may be supervised and controlled.

Various other objects of my invention relate to the provision of a system whereby the above results may be accomplished in an economical and practical manner, which employs relatively few relays per unit supervised, and which avoids the use of relays which have a necessarily delicate or critical time adjustment. Another object is to provide a system whereby the desired supervision, selection and control may be efiected over a single pair of line conductors such as those which may be found in use in a particular installation, for purposes of telephony. Still other objects of my invention will be apparent from the following description.

The novel features which I believe to be characteristic of my invention are set forth with particularity in the appended claims. My invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof may best be understood by reference to the following description taken in connection with the accompanying drawings on which Fig. 1 represents a portion of my equipment, Fig. 2 represents the receiving selecting equipment and Fig. 3 represents a number of apparatus units which are to be supervised together with the code transmitting equipment which is employed at the remote station.

Referring to the drawings I have represented at the left-hand portion in Fig. 1 a dispatchers station, indicated at A. This station is connected by means of a line L with a station B at which the remaining portion of my system is located, this portion of the system comprising the remaining apparatus indicated in Fig. 1, and in Figs. 2 and 3.

I have indicated at t and t telephone equipment which may also be used over the line L. The equipment is arranged to be cut out of circuit by a key 18 as will later be indicated.

Referring first to Fig. 3 of the drawings I have represented at 1, 2 and 3 a number of power switches which are to be controlled and supervised from the station A. I have also shown in Fig. 3 of the drawings a number of apparatus units represented by elements 4 and 5 which are movable through three or more positions, and which are arranged to be operated from one position to another through local means associated therewith or from the station A, and the position thereof indicated in the dispatchers station. These elements 4 and 5 may, for example, comprise the movable element of a meter, or the movable armature or" a rheostat whereby load control is effected. Similarly these elements may be varied in position in accordance with water level, gate positions and the like, and the positions thereof may be transmitted to the station A to indicate the reading of the meter, the load, water level, or gate position, as the case may be. Associated with each of the apparatus units 1,-5 is a control relay 1',-5. In the case of the power switches 1, 2, 3 these control relays are arranged to control the operating and trip circuits of the associated switch. In the case of the apparatus units 4 and 5 these relays may be arranged to control the motor circuit whereby the field rheostat is operated, as shown in connection with apparatus unit 4, or any other suitable circuit for controlling the position of the movable element as, for example, a motor circuit for operating a water gate. These relays are preferably of the polarized position type and are operated from a neutral position to either of two other positions in response to current of proper polarity and return to the neutral position when deenergized. For certain applica tions, however, it is desirable that certain of these relays be of the polarized two-position type which remain, when deenergized, in the position to which it was last operate Also associated with each of the apparatus units 1,-5 is an indicating relay 1' ,5." These relays are normally energized through a circuit which extends from the neutral bus 6 through the righthand contacts of the individual relays and thence, in the case of the relays associated with the power switches, to either the positive bus 7 or the negative bus 8 as determined by the position of an interlock 9, 10, 11 which is mechanically associated with each of the respective switches. Thus the relays 1", 2", 3" are normally energized in either position of the power switch. The holding circuit for each of the relays 4", 5 is permanently connected to the positive bus 7, thereby to maintain these relays normally energized. In each of these holding circuits between the coil of the corresponding relay and the positive or negative bus, as the case may be, is a resistance such as that shown at 71 in the circuit of relay The purpose of these resistances will later be indicated.

Associated with and common to all of the apparatus units supervised is a code selector switch and a code transmitter switch BS. The circuit arrangement is such that upon automatic operation of any apparatus unit 1, 2, 3, the associated indicating relay 1, 2", 3", becomes deenergized and interrupts its holding circuit. In response to this operation the code selector switch will operate from its normal position, which is that shown in the drawings, to a difierent position, dependent upon the apparatus unit which operated. When this has occurred the code transmitter switch 88 will start to rotate and in so doing, by means of either a high pitch, or low pitch, buzzer indicated at 12 and 13 respectively, in Fig. 1, will transmit to the dispatchers station a code of impulses indicating the unit which operated. A position responsive relay 14 is provided as shown in Fig. 2 whereby the code will be transmitted by either of the buzzers 12 or 13 dependently upon the position of the apparatus unit. The buzzers l2 and 13 operate to transmit high frequency impulses through a transformer 15, insulating transformer 16, line L, insulating transformer 16 of the station A to any suitable form of indicating device in the dispatc. ers station. Preferably this indicating device may take the form or" an induction howler or loud speaker indicated at 17 in the station A.

Thus the operator determine by the code which is received what apparatus unit has operated and by the pitch received from the howler the position to which the unit has operated.

After these indications have been recognized by the operator he may by pressing a reset key 18 in his station interrupt the indication and simultaneously reset the equipment at the remote station to the normal position which is that shown in the drawings leaving the apparatus unit in its operated position.

If it be assumed that the operator desires to ascertain the position of a certain remote switcl or other apparatus unit, without operating it, he will dial a code corresponding to that unit upon a suitable code transmitting device which is indicated at 20 at the station A thereby causing a code of high frequency impulses to be transmitted to the remote station. Through a selective mechanism indicated in Fig. 2 of the drawings the indicating relay c rresponding to the unit, the code number of which has been dialed will be deenergized, Deenergization of this relay will then cause operation of the code selector and code transmitting switches to transmit to the dispatchers station a code corresponding to the unit selected it the unit be a power switch, and having a pitch indicating the position of the selected unit. If the selected unit be one having three or more positions the code transmitted will correspond to the position of the unit.

In the case of the two position units such as the switches 1, 2 and. 3 the code transmitted back to the dispatchers station may preferably be the same as the code which was transmitted from the dispatchers station to the remote station to effect the desired indication. In the case of the units having three or more positions, the code transmitted back to the dispatchers station is preferably one having a number of impulses depending upon the position of the selected unit.

Having selected a desired unit by means of the selector equipment indicated at TS, 18, 2S and SS in Fig. 2 of the drawings, if it be assumed that the operator desires to change the position of the selected unit, he will then dial a further code to which a position selector indicated at 48 in Fig. 2 of the drawings responds.

This selector operates through relays l9 and 19' in Fig. l to supply current of desired polarity to the control relay of the selected unit, thereby to operate. that relay from either position to the other to effect the desired change in position of the selected unit. In the case of the two-position units such as 1, 2, 3, this change in position will cause operation of the position transmitting relay 14, which, in turn, immediately changes the tone of the code transmitted to conform with the position of the switch. In the case of the units 4, 5 the change in position will change the code transmitted.

The selecting equipment indicated in Fig. 2 is of considerable importance in connection with the reliability of operation of my invention. The equipment, as has been previously indicat-ed, comprises primarily the selector switches TS, 18, 25, 3S and 4S, together with a group of relays, of which 39 and 82 are indicated in the drawings. These selector switches are of well known construction comprising a plurality of wipers which are actuated over a bank of contacts in a step-by step manner by means of a suitable motor magnet through a ratchet and pawl arrangement. If desired svitches of the type shown in United States Patent No. 1,472,- 465, Oscar F. Forsberg et al., issued October 30, may be employed. It may be mentioned here that the switches 58 and GS of Fig. 3 are of the same construction. While any desired number of contacts may be employed in the banks of the different switches, for most purposes, the switches TS, IS, 33, 4S preferably include 11 contacts on each bank, whereas the switches 23, 5S and 6S include twenty-five contacts in each bank.

For convenience in description, I choose to term the switches 1S, 2S and 3S collectively either with or without the switch TS, the apparatus units selector the switch TS the transfer selector" and the switch 48 the position selector. corresponding legends being applied to the drawings.

To obtain the desired degree of reliability the code corresponding to each apparatus unit preferably includes three or more groups of impulses, the appa .tus Lmit selector, including, in addition to the transfer selector, a selector switch corresponding to each group of impulses in the different codes. The function or" the transfer selector is to supply each group of impulses received in any code to the motor magnet of the appropriate selector switch and at the end of the code to connect the position selector to re spond to any further code which may be r ceived. In this manner the selector switches 13, 2S, and 3S are respectively positioned in response to its appropriate group of impulses and serve thereby to select a particular apparatus unit. The position of the selected unit may then be controlled by further codes to which the position selector responds without further operation of the apparatus unit selector mechanism.

The advantages of this method of selection will later be pointed out.

Having now briefly indicated the character of the equipment to be disclosed its more detailed structure and operation will now be more fully explained.

Located at the station A is a high frequency code transmitting device comprising a dialing device 20 and an induction coil 22, the induction coil 22 having a primary winding and a secondary windin The primary winding of the coil 22 is connected in circuit with a pair of interrupter contacts 22 on the induction coil, dialing contacts 23, and battery 24. The secondary winding of the induction coil is connected in circuit with one winding of the insulating transformer 16 at the dispatchers station through a pair of normally open contacts 25 which are controlled by the dial 2D. This winding of the transformer 16 is also normally connected in circuit with the induction howler 17 through normally closed contacts 26 controlled by the dial 20.

The dialing device 20 is of a well-known construction, used in telephone practice, and is so ar anged that when operated from its normal posi on, it opens the contacts 26 thereby interrupting the circuit of the induction howler and closing contacts 25 thereby completing the circuit of the secondary winding of the induction coil. Vi'hen released the dial returns to its normal position under influence of a suitable biasing spring, or other mechanism, and periodically closes the contacts 23 a number of times depending upon the extent of movement of the dial from its normal position. After it has returned to its normal position it will again open the contacts 25 and close the contacts 26, thereby again connecting the howler in circuit with the transformer 15. Thus a code of high frequency impulses will e transmitted over the line L.

At the remote station the relay 27 is connected across one of the windings of the transformer 16' such that it responds to the high frequency impulses received from the dispatchers station. In circuit with this relay is a filter comprising an inductance F and a condenser F for preventing low frequency and direct current impulses on the line from operating the relay 27.

Let us assume that the operator dials the number corresponding to the switch 2 at the remote station thereby to ascertain the position of that switch. The code number of this switch, as indicated on the drawings, is 239. The operator will then dial this number upon his dial 20 in the usual manner, thereby sending three groups of impulses having 2, 3, and 9 impulses respectively, the groups of impulses being separated by a time interval greater than the time interval between impulses of any group.

Relay 2'? at the remote station responds to these high frequency impulses thereby closing an obvious circuit between the positive bus 8, which is connected to bus '7 and the negative bus 8 through the actuating winding of relay 28. Relay 28 thus follows the operation of relay 2'7, and energizes relay 29 through an obvious circuit between the positive bus '7 and the negative bus 8. Upon each operation of relay 29 a circuit is completed which extends from the positive bus '7 through the right-hand contacts of relay 29,

bank TS-Z of selector switch TS and motor magnet 31 of the switch 1S to the negative bus 8. The motor magnet 31 is thus energized twice in response to the first group of impulses of the code and, upon each deenergization thereof se- 1 ctor switch 1S is moved from the normal position to its second off-normal position.

It will be seen that relay 32 is energized upon each energization of relay 29 through an obvious circuit. This relay is slow to release, and its armatures are not operated between the impulses oi the respective groups. 2-1 wever, the time delay characteristic of this relay is such that the armatures of this relay are operated to the normal position shown in the drawing during the time interval between groups of impulses thereby completing a circuit which extends from the negative bus 8 through the motor magnet 33 of the transfer switch TS, interrupter contacts thereof, conductor 135 right-hand contacts of relay 32, contacts 34' of relay 3e, conductor 35, wiper and normal contact or" bank TS-3, wiper of bank 1S1 in second. position and conductor 35 to the positive bus '7. Thus motor magnet 33 is energized and in operating interrupts its own circuit thereby stopping the transfer switch on to its 1" rst olinormal contact.

When the second goup of impulses is received motor magnet 33 will be operated through a circuit extending from the positive bus 7 through the right-hand contac s of relay 29, wiper and first contact of bank TS-2, and motor magnet so to the negative bus 3. lhus the motor magnet 36 will operate the selec 0" switch 28 to its tllrd oiinormal contact, since there are hree impulses in the second group of the code transmitted. At the end of the group, relay 32 again becomes deenergized and in operating to its normal position again energizes motor magnet 33 of the transfer selector, the circuit now extending from the negative bus 8 through the motor magnet 33 and its interrupter contacts, conductor 135 right-hand contacts of the relay 32, contacts 34' of relay 34, conductor 35, wiper and first contact of bank TS- wiper and third contact of bank 2S--1 and conductor 35 to the positive bus '7. Motor magnet 33 will then operate the transfer selector to its second off-normal contact.

In respon e to the next group of impulses motor magnet 3'7 will be energized, this circuit extending from the positive bus '7 through the righthand contacts of relay 29, conductor wiper and second contact of bank IS2, and motor magnet 37 to the negative bus 8. Since there are 9 impulses the group, selector 3.8 will operatcd to its ninth position. At the end of this group of impulses relay 32 is again deenergized and advances the transfer switch to its third position, the circuit extending from the negative bus 8 through the motor magnet 33 and its interrupter contacts, conductor right-hand contacts of relay r 5 relay conductor 35, wiper e r tact oi oank wiper h contact of bank 355-1 and conductor to the positive bus '7.

It will thus be seen that in response to receipt of the code the switch is is operated a number oi times dependin upon the number of impulses in the first group of the code, after which the transfer selector is operated to interrupt the circuit of the motor magnet oi switch is and to connect in circuit the motor magnet or the switch 2S. Switch 2S .then responds to the second group of the code after which the transfer selector is again operated to interrupt the circuit of its motor magnet and to connect in circuit the motor magnet of the switch 36. Switch 38 then responds to the third group of the code after which the transfer selector is again operated to interrupt the circuit of its motor magnet and to connect in circuit, as will later be indicated, the motor magnet of the switch as. This completes the apparatus unit selecting operation.

The circuits are so arranged that an apparatus unit selected "11 response to the relative posi tion of the diiierent switches the apparatus unit selector.

Thus in the case assumed wi h the selector TS in engagement with its third oil-normal contact, selector 1S in engagement with its second off-normal contact, selector 28 in engagement with its third off-normal contact and selector SS in engagement with its ninth ofi-norrnal contact, a circuit willbe completcdwhich extends from the posi tive bus '7 through conductor 38, wiper and second contact of the bank lS-2 wmding of relay 39, conductor 40, wiper and third contact of the bank 25-2, wipe and ninth contact of the bank. 3S-2 conductor 41, and wiper and third contact or bank IS-4 back to the negative bus 8.

The groups of relays 39, 82 I choose for convenience to term short circuiting relays for a reason resently to be indicated. Short circuiting relay 39 now energized by means of its left-hand cor 'acts completes a short circuit connection which extends from the neutral bus 6 through the left-hand contacts of relay 42, lefthand contacts of relay 39, wiper and third contact of the bank 2s e, conductor 43, winding of relay 2 and its right-hand armature back to the neutral conductor 6. This connection short circuits the winding of relay 2 which then deene zes at its right-hand contacts opens its holding circuithich has been previously traced.

At its left-hand contacts relay 2" completes a circuit which extends from the positive bus '7 through condu tor lei, left-hand contacts of relay conductor .5, windin of relay 46 to the ieg 'lve At the same time at its middle contacts relay 2 interrupts a connection from the positive bus through conductor 44 to the eighth contact on bank: 5S5 for a purpose later to be indicated.

Energization of relay 46 completes a circuit which extends from positive bus 7 through the left-hand contacts of relay 4S, winding of relay 4?, conductor 48, contacts .9 on relay 50 of Fig. l, conductor i8, interrupter contacts, and motor magnet 52 of the switch ES to the negative bus 8. Relay 47 does not energize in this circuit for the reason that it is short middle contacts of relay 4e, conductor 53, normal contact and wiper of bank 5-8-5 back to conductor 4s. Motor magnet 52. however, energizes and its interrupter contacts deenergizes itself, ad-

vancing switch OS to its first cit-normal contact.

Since the off-normal contact of the bank .ES-S is connected to positive through the middle contacts of relay 1" and each successive contact of the bank 5S5 similarly connected through contacts on similar relays, not shown, corresponding to other switches which are supervised by the positive bus the motor magnet will again energize upon each successive step of the switch until the switch reaches its eighth contact.

As was previously indicated, the eighth contact is disconnected from the positive bus by operation of the micelle contacts of relay 2 and, accordly, in this position operation of the switch 58 circuitecl through the j v -rterripted. The short circuit about the winding of relay 47 is now removed, and this relay energizes completing a circuit which extends from the negative bus 8 through the left-hand contacts of relay 4'7, conductor 54, normal contact and wiper of the bani: 68-4, conductor 65, interrupter contacts on motor magnet 66, conductor 67, winding of relay 68 and conductor 38 to the positive bus '7. Relay 68 then energizes and through its right-hand contacts completes an obvious circuit for relay 69. Relay 69 then energizes and completes a circuit which extends from the positive bus '7 through conductor 38, contacts on relay 69, conductor '20 and motor magnet 66 of the switch 63 to the negative bus 8. The motor magnet 66 energizes and in operating its interrupter contacts deenergizes the previously traced circuit for relay 68. Relay 68 then deenergizes relay 69 which in turn deenergizes motor magnet 66. Upon closing its interrupter contacts the motor magnet 66 again energizes relay 68, this cycle of operation repeating itself, and the switch advancing one step upon each deenergization of the motor magnet 66.

Thus, in response to operation of any of the indicating relays the selector switch 58 operates over its contacts to a position corresponding to the particular indicating relay operated. The switch 6S, which I choose to term the code transmitting switch, then continuously rotates and transmits a code to the dispatchers station corresponding to ie position to which the switch 55, which I choose to call a code selector has operated, this position corresponding to the apparatus unit selected. Thus, in the case assumed, as will be presently indicated, the code transmitted to the dispatchers station will be 2-3-9. This code will be transmitted in high frequency impulses produced by one or the other of the buzzers 12 or 13, depending upon the position of the apparatus unit selected, the buzzer being operated under control of the code transmitting switch 6S and the code selector switch 55.

To alternately connect the buzzers 12 and 13 in circuit, depending upon the position of the selected apparatus unit, a code transmitting relay 14 is provided. This relay is common to all the apparatus units and is connected in circuit with the interlocking contacts of the selected unit by means of the bank 53-1. Thus the circuit for the relay 14 extends from positive bus '7 through conductor 38, winding of relay 1 1, conductor 94, wiper 5S-1 on its eighth contact, resistance '71, and interlock switch 16, in its lower position to the positive bus '7. Thus both terminals of the relay 14 are connected to the positive bus, and the relay is thus short circuited and deenergized. Its right-hand contacts are thus separated thereby interrupting a circuit extending through conductor 72 to the high pitch buzzer 12. The leftcontacts of relay 1% are closed and complete a. circuit which extends from the positive bus '7 through the right-hand contacts of relay 4'7 which. now closed, contacts of relay '73, lefthand con acts of relay 68, lefthand contacts of conductor '75, low pitch buzzer 13, primary winding of output transformer 15 back to the negative bus 8.

As has previously been indicated relays 68 and 69 operate aiternately in a cycle with the motor magnet 65 to rotate the switch 68. These relays .re slow to release and operate in a proper period "ied by the time-d lay means associated with, and which are indicated in the drawto rotate the switch 655 at a speed which It will be seen that the above circuit for the low pitch buzzer 13 is completed upon each step of the selector switch, i. e. on each energization of relay 68, provided that the contacts of relay '73 are closed. In order to interrupt the operation of buzzer 13 in accordance with a desired code, this relay 73 is provided. This relay is connected in a circuit which extends from the negative bus 8' through conductor '76, winding of relay '7 3 to conductor '77, and thence intermittently through banks SS-l, 53-3 and 58-4 in a manner presently to be indicated, to conductor '78, and the left-hand contacts of relay to the positive bus 7. Thus, whenever the above traced circuit is completed between the conductors '7'7 and 78, the relay '73 will be energized and the operation of the buzzer will be interrupted.

It may be well at this point to indicate the nature and operation of the buzzers 13 and 12. These buzzers each comprise a magnet having an armature and a cooperating contact whereby when the magnet is energized the contacts close and short circuit the winding of the magnet. These windings are connected in series with the primary winding of the output transformer 15 such that when the magnet is short circuited the current through the primary winding of the transformer is increased until the contacts separate. The winding of the magnet is then inserted in the circuit causing the current in the primary winding of transformer 15 to reduce until the contacts of the buzzer again close, this operation continuing and high frequency currents being produced in the circuit of the secondary winding of the transformer 15 and condenser 15 having a pitch determined in accordance with the structure, as for example the length of the armature, of the buzzer. These high frequency currents are supplied through the transformer 16 line L, and transformer 16, to the induction howler 17 at the dispatchers station.

Th above indicated circuit for relay '73 will be completed between conductors '7'7 and '78 in the case assumed, when the switch BS is on its normal position through wiper (SS-1 and conductor '79. The circuit will then be interrupted until the wiper of 68-1 reaches its third olfnormal contact, at which time the circuit will be completed through said third off-normal con tact, conductor 80, and the 8th contact of Wiper 5S-4. The circuit will again be interrupted when the wiper 6S-1 leaves its third contact and until it engages contact '7 at which point the circuit is completed through said seventh contact, conductor 81, and the eighth contact and wiper of 1-30 bank 58-3. The circuit will then be interrupted at 68-1 until wiper 63-1 engages its seventeenth contact where it will again be completed through contacts 1'7 to 24, which are strapped together, of wiper (SS-1 and conductor 135 '79. Thus relay '73 will be energized when the wiper of bank 68-1 is on its zero contact, third, seventh and seventeenth to twenty-fourth contact, and the operation of buzzer 13 will be interrupted in these positions of the switch 68. The code transmitted will then be 2-3-9, this code being the code transmitted from the dispatchers station, and which corresponds to the apparatus unit selected.

The operator is now informed by the code received that the transmitted code has been properly received at the remote station, and that the apparatus unit selector has functioned to select the correct apparatus unit. He is also informed by the pitch of the received code as to the posi- 159 tion which the selected apparatus unit occupies.

It will now be understood that had the code transmitted by the dispatcher consisted of 21G-2 rather than 23-9 the switch 18 would engage its second contact, the switch 23 its tenth contact and the switch 353 its second contact. Relay 39 would likewise, have been energized but the indicating relay 1" would have been short circuited and deenergized. Deenergization of relay 1' removes positive potential from the first ofi-normal contact of bank 5S-5 and, accordingly, after operation of relay 46, switch 58 would have operated to its first off-normal contact. The code transmitted would then have been 2-10-2 as will be obvious from the description already presented.

Had the code transmitted by the dispatcher been 3-92 the switch 1S would engage its third contact, the switch 28 its ninth contact, and the switch 33 its second contact. Relay 82 would have been energized rather than relay 39, and this relay would have operated to short circuit the winding of relay 3" through a circuit extending from the neutral bus 6 through the left-hand contacts of relay 42, left-hand contacts of relay 82, ninth contact of wiper of bank 2S5, conductor 83, conductor 83 through the Winding and right-hand armature or relay 3" to the neutral bus 6. Thus relay 3 would have been deenergized and have operated through the relays 46, 4'7 and selectors 5S and 68 to transmit the received code back to the dispatchers station in a pitch corresponding to the position of transmit a code to the dispatcher.

While in the rawings only two short circuiting relays 39, 82 are indicated, it will be apparent that a greater number of these relays may be employed dependently upon the number of integers in the first digit which it is desired to use in the codes corresponding to the diiierent apparatus units. It will be seen that one terminal of the windings of each of these relays is connected to a contact in the bank 1S-2 such that the relay operated is dependent upon the position of the first selector switch IS. The circuits of these relays also extend through each of the other switches TS, 2S and 353 such that these relays will not be energized unless the different switches are in engagement with their proper contacts. Similarly the connections of the contacts on these relays 39, 82 whereby the indicating relays are short circuited extend through wiper and contacts on the switch 2S such that the relay short circuited is dependent upon the position of this switch. In the same way the control relays 1', 2, 3', 4', 5' are all connected to individual contacts on the switch 3S and extend through contacts of relay 39 or 82.

. In the use of the codes employed it is preferable that the total number of impulses in the different codes, corresponding to each of the different units supervised, should be equal for all codes and that each code should comprise three, or if more selector switches are employed, a correspondingly greater number of groups of impulses. In this way great reliability of the equipment is accom plished, and the possibility of the selection of an incorrect apparatus unit is rendered remote. In fact the circuits or relays 89 and 42 are so arranged that the addition, or omission, of an impulse in any group of any code will result in neither of these relays being energized and therefore the operation of th code selector 5S and the code transmitter 5S is not efiected to Since the dispatcher receives no signal after sending out a code of impulses, he knows that no selection has been made by the impulses transmitted from the dispatchers station. In this way great security is had against selection of an incorrect unit either due to surges in the line L or due to faulty contacts on any of the relays or on the dialing device.

Having determined by the code received that the proper apparatus unit 2 has been selected, let us assume that the operator desires to operate this unit, comprising a circuit breaker, from its open position, to its closed position. To accomplish this the operator will dial an additional code of five impulses. Relays 27, 28, 29 respond to these impulses, the relay 29 completing a circuit which extends from positive bus 7 through the righthand contacts thereof, conductor 30, wiper and third contact of the bank TS-2 and motor magnet 84 or" the position selector 48 to the negative bus 8.

Since the circuit of the motor magnet 33 of the transfer selector is now interrupted at the wiper of bank TS3 on the third contact, this switch will not be actuated when the relay 32 becomes deenergized at the end of this additional code, but will remain in the position which it occupied at the end of the apparatus unit selecting operation. The position selector 48 will be operated in response to this additional code to its fifth contact thereby closing a circuit which extends from the positive bus 7 through conductors 85, 51, right-hand contacts of relay 100, left-hand contacts of relay 32, conductor 86, wiper and fifth contact of bank 4S4, conductor 87, winding of relay l9, left-hand contacts of relay 19 and right-hand contacts of relay 88 to the negative bus 8. Relay 19' will thus be energized thereby completing a circuit which extends from the negative bus 8' through contacts 89 on relay 19, conductor 1G6, left-han contacts of relay 99, conductor 91, middle contacts on relay 89, wiper 3S-4 on its ninth contact, conductor 92, polarized control relay 2', conductor 93, righthand outer contacts on relay 19 and conductor 95 to the positive bus I. The polari y of current flowing in this circuit will be such as to operate the relay 2' to close the switch 2.

When the switch 2 is operated to its upper position the short circuit around the relay 14 is removed and this relay becomes energized through the previously traced circuit extending from the positive bus '7 through conductor 38, winding of relay 14, conductor 94, wiper and eighth contact of the bank 5Sl, resistance '71 and switch 10 T in its upper position to the negative bus 8. Relay 14 will then be energized thereby interrupting the circuit of the low pitch buzzer l3 and substituting in circuit the high pitch buzzer 12. Thus the operator is informed that the position of the f f switch is changed. If the switch now chang position automatically it will be seen that the pitch of the code will at 0 cc be changed.

The code transmitting switch GS of course continues to revolve persistently transmitting the is of the slug type, slow releasing relay, it will remain energized until the position selector 4.6 has its normal position. Relay 19 also completes a circuit which extends from the positive bus 7 through conductor 85, conductor 95, contacts 99 on relay 19 and winding of relay ice to the negative side of the battery. At the same tiine relay 19 by its left-hand contacts i rupts the circut of relay 19 to prevent any possibility of these relays becoming energized at the same time.

Upon operating relay circuit for itself which e e bus 8 through the o i hand contacts thereof, conductor 101 and bank 48-2 and its associated wiper to the positive bus '1. t the time means of its right-hand l contacts it interrupts the original ene "gizing cirf By means of its middle cv conductor 1G2, middle contacts of relay loo, cow cluctor sank LS-31 all of the off nornxal contacts of which are strapped together, associated wiper to the positive bus The motor iagnet 84 then operates as a buzzer to restore e switch as to s tial position where it is or the next operation relays l9 and becoi -ing deenergized when the position selector the no ma-l positionv If the operator desires to operate the c cuit broa or 2 to open position, he w ll dial an additional code of three impulses. 3- y responding to these impulses will spondingly energize the moto net 8 through the previously traced CliCCilL thereby advancing t e no tion selector is to its third contact 1 position a circ is completed which extends negative bus 8 through the right-hand cent of relay 8S, left-hand contacts of i are now closed, win A 104, third contact or A Wiper oi the bani conductor 86, mend contacts of relay 32,

right-hand co 7. Upon energizing, circuit for itself w f the negate bus 8 through the l l d contact-s 0. relay 88, left-h nd contacts of lelay l9, coil of relay 19. contacts 195 of the relay conductor 17, contacts 3 to 10 and wiper of the bank and conductor to the positive bus '7. The

similarly with relay 1%) is slow to releo e and, hence, remains energized until the s ch 43 reaches its normal contact when it becomes cleenergized. At the same time, by closing its contacts 197, it connects conch: tor 106 to positive battery through conductors and 8 means of its right-hand outer conta nects the conductor 3 to the negative so doing it reverses th polarity of curls in the winding of polarize tial of one polarity to the selected control relay and when the p tion selector is op-c'ated to its t 1 contact rela i9 bosom-es energl to supply potential of the opposite polarity to the selected control relay.

Upon operating by means of its conta relay l9 completes a circuit from t e nose 8 through the \vir 109, 51 85 to the positive bus 7. Relay 16G then energizes and, by means of its left-hand contacts, completes a holding circuit 1 r itself which extends through its l t-hanC contacts, 001 ductor 1G1, contact and banl: 85, to the positive LS tact it interrupts energizing circuit for 19. At its middle contacts it again completes the buzzer circ for the motor magnet 84 of th cosition selector 1 is circuit extencling, as previously indicated, through conductors 102 and 163 and the bank 453-4 and wiper or" the position selector to the positive bus '7 and negative bus 8'. victor magnet 84 then operates the position selector to the normal position Where buzzer circuit is interrupted at the normal ontact of bank LS-l. Similarly this position holding circuit of relay 1% is interrupted at the normal contact of ba k 1S2 and the hold.- ing circuit of relay 1% is i terrupted at the norcontact of bank 4S-3 thereby restoring these relays to their normal positions.

It will be seen that all of the on? normal contacts in bank iS-4 with the exception or contacts the t iird and fi th are connected together. The purpose or" thi to establish the buzzer circuit for motor magnet 84 in case the switch 13 stops on any contact other than 3 or 5. This is brought about through operation of slow releasi 9; relay 88 which becomes energized, v Len this contingency occurs, through a circuit extending from negative bus 8', through relay 88, conductor 88. contacts and Wiper bani; 4e 1, conduct-or 86, left-hand contacts of relay 32, right-hand contacts of relay 1% and conductors 51 and 85 to the positive bus 7. The relay 88 then operates and at its right-hand contacts interrupts the circuit the wind gs of relays 19 and 19. At its left-- hand contacts it completes an obvious circuit for relay 10c. Relay 1% then operates and at its inidclle contacts completes the above traced buzzer circuit of motor magnet The time of drop ou of relay 83 is such that the i tor mag et operates the switch 45 over the third and fifth contacts without interruption. The switch as now returns rapidly to zero when it tops due to interruption. of the buzzer circuit of the normal con-- tact of bank LS-1. Relays 88 and 196 now reparatus unit been selected the operation of the selected unit can be effected only in response to surge upon the line, or a faulty contact,

operation Will result, position selector lflll'l'iS- y returning to its initial position in read ness for a further operation by the dispatcher. will further be seen that after the apparatus unit has been selected it may be operated back and forth as many times as desired without changing the position of the apparatus unit selecting mechanism, only one apparatus unit selecting operation bein necessary to efiect any desired number of control operations of the selected unit After an apparatus unit has been selected and the indication of the position thereof received, the operator may, if he desires, then restore all the equipment to the initial position without operating the selected unit. This is effected by operating a reset key 18 at the dispatchers station from its normal position to its right-hand position. Similarly this may be efiected at any other time in the operation of the equipment, either before or alter a remote control operation has been eiiected, or at a time when the selectors of the position selector are in such position, due to incorrect operation, that no unit is selected.

Resetting of the equipment is brought about as iollows: hen the reset key 18 pressed to its right-hand position a direct cur-reinu impulse is produced from battery 109 in the pr winding of the transformer 16 thereby producing a direct current impulse in the output winding of the transformer 16 at the remote station. The reset relay 110 at the remote sta ion responds to this impulse. Tl s relay has two windings, the left-hand winding of which is connect-- ed to the transformer 16' the right-hand winding oi which constitutes a holding winding which is connected in a circuit extending from the positive bus 7 through the right-hand contact of relay 50, and right-hand wind 1g of relay 110 to the negative bus 8. The curl ,nt flowing in the right-hand winding of relay 110 is not sufficient to opera e the relay although, after the relay has been operated by its left-hand winding, it will be retained in its operated condition by this winding after the operating impulse in the left-hand winding has ceased.

Upon operating relay 110 completes an obvious circuit for relay 50. Relay operates and by means of its contacts 111 completes an obvious circuit for relay 90. It also interrupts the holding circuit of relay 115 at its right-hand contacts which relay drops out. Relay 90 then operates and by means of its contacts 112 completes a hol circuit for itself around the contacts 111 through a circuit which extends from the positive bus '7 through the contacts 112, righ -hand contacts of relay 113, which are now closed and winding of relay 9D to the negative bus 8. Relay 113, it will be seen, is energized whenever any of the switches TS, 18, 3S and 4S is engagement with an oil-no" .21 contact,

1 -.ts circuit extending directly from the negative bus 8 through conductor 114, interrupter contacts on all the said switches, connected in parallel to the positive bus '7. These interrupter contacts may be in the form of a wiper which engages a continuous conducting bar in any off-normal position, or a. bank of contacts which are strapped together, or any other contacting means mechanically associated with the respective switch in a manner such that the circuit is closed therethrough whenever the switch occupies an of-normal position.

When during the selecting operation re u 2, operated, it by means of its right ontacts, completed a ircuit which extend: from e negative bus 8 through relay 12, right-hand contacts of relay 46, and contacts on one of short-cirouiting relays 82; 2-9 in the case assumed, to the positive 7. Re when ener ized. interrupts the short circun across the windin of the selected indicati leaves the selected relay in con energized d" log the resetting operation.

This fLlIlCJlOll is accomplished by relay 50 energized, the resetting circuit extending r" the neutral bus 6 through contacts 115 of so, conductor 116, wiper 5S-2, in engagement with its eighti contact, winding of relay 2", and switch 10 in its lower position, in the case assumed, to the positive 7. the switch 2 been in its upper position t s circuit would have been completed to the negr 176 bus 3. In either case the relay 2" is energized and, upon operat ing, completes its holding circuit through its right-hand contacts.

It will be seen that by of the bank 5S2 this resetting circuit for the indicating relays is selectively connected to relay associated with the selected apparatus unit.

Energization of relay 2" decner es relay as and, at the same time, through its ddle contacts supplies positive potential to the eighth contact of the bank 5S5. Deenergiration of relay l6 interrupts the supply of positive potential to the normal contact of 5S-5. Since relay 50 is energized and its contacts pen, the

circuit of the motor magnet and interrupter contacts of switch 555, which extends from the wiper 5S-5 through conductor 18, contacts is and conductor 48, to the motor magnet and thence to the negative bus 8, will remain deenergized and the switch 53 will remain on its eighth contact until relay 59 again deenergizes.

As was previously stated relay 50 tacts 111 energizes relay 9O whic', holding circuit for i'self around the of relay 50. Contacts 11'? of relay an obvious circuit for relay 34. ates and by means of its left-ha d contacts interrupts the holding circuit r-lay 50. Since I original energizing circuit or relay 50 was in erupted en the reset relay 110 released, relay 50 will now be deenergized. 50 now closes its contacts thereby establis n'ng the buzzer circuit through inotor magnet 52 of selec tor switch 555 and contacts of the bank firs-5 of that switch. The switch 55 will then return to its normal position where the circuit is interrupte' at the middle contacts of relay 46. In this position of switch 5S relay 118 will be energized for a purpose later to be indicated, through a circuit extending from the negative bus 8 through conductor 76, relay 118, conductor 119, norm contact of bank 5* conductor '78, and left-hand contacts of rela lye bus '7.

Deenergization of relay to de energization of relay 4:5 interrupts the supply or" negative potential though its left-hand contacts and conductor 5% to the normal contact of the bank (SS-. Switch 63 will then operate around to the norznal position where relay 68, and hence, relay 69 and motor ma net 65 will become deenergised and operation will cease. This interrupts the transmission of the code to the dispatchers station.

When switch 63 reaches its 1101'" rel position relay 12o will be energized also for a purpose lat-er to be indicated through a circuit extending from the negative bus 8, conduct r '76, relay 120, conductor 121, wiper and normal contact 0 the bank 68-3 and conductor 122 to the positive bus 7.

Relays 9G and 34 which are now energized, and which have established holding circuits for themselves reset the balauce of the equipment, as

by its concompletes a contacts 111 99 complete clay 34 operiii:

follows1-By means of contacts 122 on relay 90 a circuit is completed which extends from the positive bus 7 through conductor 85, wiper and contacts of the bank 1S-1, conductor 123, contacts 122 on relay 90; conductor 124, and interrupter contacts, and motor magnet 31 of selector switch 18 to the negative bus 8. This establishes a buzzer circuit for the motor magnet 31 which then serves to operate the switch 13 to its normal position where the buzzer circuit is interrupted. at the wiper of bank 1S-1. Contacts 125 of the relay 90 complete a similar circuit for the switch 28, this circuit extending from the positive bus at conductor 85, through the wiper 255-1, conductor 126, contacts 125, conductor 127, and interrupter contacts and motor magnet 36 of the switch 23 to the negative bus 8. The motor magnet now operates the switch 28 to its normal position where the circuit is interrupted at the wiper of bank 25-1. The outer right-hand contacts of relay 90 also complete a similar circuit for the switch 3S, this circuit extending from the positive bus at conductor 85 through the wiper and bank 33-1, conductor 128, outer right-hand contacts of relay 90, conductor 129, interrupter contacts and motor magnet 37 of the switch 33 to the negative bus. Thus all of these switches are now operated to the normal position.

The transfer selector is reset as follows: Upon operation of relay 34 a circuit is completed from the positive bus at the conductor 85 through the bank TS-l of the transfer selector, conductor 130, contacts 131 and 132 of relay 34, in series, conductor 135 and interrupter contacts and motor magnet 33 of the transfer selector to the negative bus 8. The transfer selector will then be operated to the normal position where the circult is interrupted at the normal contacts or" the bank TS-i. Separation of contacts 34 on relay 34 prevents the motor magnet of TS from becoming energized through 18-1 in case TS reaches the normal position before 18 reaches that position.

When switch 2S reaches its normal contact it completes an obvious circuit through its wiper and bank 253-1 for relay 136 which now becomes energized. Similarly when switches TS, 13, 3S and 4S reach their normal positions their auxiliary contacts 33', 31', 37' and at which are connected in parallel, deenergize relay 113 which returns to its normal position. With relay 113 deenergized and relay 136 energized, the holding circuit for relay 90 is interrupted. Relay 90 in droppin out, by means of its contacts 117, interrupts the circuit of relay 3e. Relay 3 1 then becomes deenergized and by means of its righthand contact deenergizes relay 100. Thus all of the equipment is now restored to its normal position, which is that shown in the drawing.

Should the operator later desire to check the condition of the remote equipment and also the condition of his line conductors, he may do so by again pressing his reset key. If the equipment is in its normal position this operation will produce, in a manner now to be described, a short low pitch tone at the howler 17.

As was previously indicated when the equipment returned to its normal position relay 113 became deenergized and relays 136, 118, and 120 became energized. Accordingly, when the operator again presses his reset key and the relays 11c and 5c respond, a circuit will be completed for a short time which extends from the positive bus 7 through the inner left-hand contacts of relay 50,1eft-hand contacts of relay 113, righthand contacts of relay 136, conductor 137, contacts of relays 118 and 120 in series, conductor '75, low pitch buzzer 13 and primary winding of transformer 15 to the negative bus. Thus a short low pitch tone will be produced in the howler indicating that the equipment is in the normal condition. This tone will be interrupted when relays 110 and again become deenergized.

Let us assume that, with the apparatus in its normal position, one or more of the circuit breakers l, 2, 3, changes its position either due to accident or to control through some automatic control equipment not indicated in the drawings. When the interlocking switches 9, 10, 11 on any of these apparatus units is operated from one position to the other the holding circuit of the associated indicating relay is momentarily interrupted, and the potential supplied thereto through the interlocking switch is reversed. This interruption and reversal of potential causes the associated indicating relay to drop out and, in dropping out, its right-hand contacts will interrupt its holding circuit, its middle contacts will interrupt the supply of positive potential to one of the contacts in the bank 58-5, and its left-hand contacts will energize relay 15 all in the manner previously described. Relay 46 will then pick up and supply potential, as before, to the normal contact oi the bank 5S-5 and, hence, through conductor 48, contact 49 on the switch 50, and conductor 43 to the motor magnet 52 of the switch 58. The switch 58 will then operate to the first contact which is connected to an operated indicating relay. Energization of relay 47 will then supply negative potential to the normal contact of the bank 68-4 and thence, as previously described, establish operation of the relays 68 and 69 in conjunction with the motor magnet 66 to rotate the selector switch 68, this operation having been previously described. A code will then be transmitted in accordance with the operated apparatus unit. All of the selecting equipment including the apparatus unit selector and position selector will remain in its normal I position. It will he noticed that this code indication will be persistently indicated at the dispatchers station in a tone indicating the position to which the remote unit has operated.

The operator having determined from the received indication which of the remote switches operated and the position thereof he may now interrupt the transmission of the code by again pressing his reset key. This operation will as be fore, provided but one remote apparatus unit operated, reset the operated equipment to the normal position. If, however, two or more remote apparatus units simultaneously changed position, and their corresponding indicating relays became deenergized, it will be apparent that positive potential will have been removed from each of a plurality of contacts in the bank 58-5, each contact corresponding to the indicating relay associated with an operating apparatus unit. Since operation of the switch 58 is interrupted when the switch reaches the first contact in the bank -5 from which positive potential has been removed, it will be apparent that only the indicating relay associated with these contacts will be restored to its energized condition through 5S-2 when the reset key is pressed. After restoration of this relay it will be seen that the switch 58 will operate to the next contact in the bank 58-5 from which potential has been removed by the operation of another apparatus unit where its operation will be interrupted. A code will now be transmitted indicating the next apparatus unit which operated in a tone corresponding to the position to which the next unit operated. After a successive operation of the reset key switch 55 will again operate to a further contact from which potential has been removed by operation of an apparatus unit and a corresponding code will be transmitted to the dispatchers station or if no further apparatus unit has operated then the switches 5S and 68 will return to their normal position and stop, thereby interrupting the code.

It will thus be seen that when the operator receives an indication informing him of the automatic operation of a remote unit, he is not at once informed that more than one unit operated. He may then press his reset key, and if indications cease, he is informed that no further unit has operated, but if a further unit has operated, the code will at once be changed to correspond to the next unit operated, and the tone will change to correspond to the position thereof. Again pressing the reset key will inform the operator of operation of any further apparatus unit.

As has been previously stated, equipment constructed in accordance with my invention may be employed to indicate the position occupied by apparatus units having three or more positions as well as those having only two positions, and that with the addition of very little equipment my system may be used for the indication and control of apparatus units, some of which have but two positions and others of which have a large number of positions.

It will be recalled that associated with each of the apparatus units 4, 5, having more than two positions, is also an indicating relay 4", 5" respectively. Also associated with these apparatus units and common to all of them are a group of relays 14s, to 149, the number of these relays employed being dependent upon the maximum number of positions of any of the apparatus units, and each relay corresponding to one position of the different apparatus units. These various apparatus units are provided with a bank or" contacts 150, 151 over which they operate in moving through their various positions, the corresponding contacts of which are multipled together and connected to a corresponding relay in the group 140149. The arrangement is such that upon deenergization of the indicating relay corresponding to any apparatus unit the relay in the group 140 to 149 corresponding to the position of that unit will be energized thereby causing the code transmitting switch 65 to transmit a code indicating the position of the apparatus unit. The more detailed operation of the equipment in performing the function of indicating the position of apparatus units having three or more positions will now be set forth.

Let us assume that the operator desires to ascertain the position of the apparatus unit 4. He will dial the code 2-2-10 thereby operating the switch 18 to its second off-normal contact, switch 2S to its second off-normal contact, and switch 35 to its tenth off-normal contact. transfer switch TS remaining in engagement with its third ofi-normal contact. The short circuit for the indicating relay 4 will then be completed from the neutral bus 6 through the left-hand contacts of relay 42, left-hand contacts of relay 39 which is now energized, wiper and second contact of the bank 2S-4, conductor 152, conductor 153, winding of relay 4" and its right-hand contacts to the neutral bus 6. Relay 4" is then short circuited and deenergized and completes a circuit extending from the positive bus through conductor 44, left-hand contacts of relay 4", apparatus unit 4, which we will say is on its sixth contact, and winding of relay 145 to the negative bus 8. Relay 145 then operates and, by means of its light-hand contacts, closes an obvious circuit for relay 140.

At its contacts 154 the relay 4" closes the circuit for relay 46, and at its contacts 155 it interrupts the supply of positive potential to the ninth contact of the bank 5S5. Relay 46 then energizes and, as before, through its right-hand contacts energizes relay 42 thereby removing the short circuit from the winding of relay 4". At its middle contacts it supplies positive potential to the normal contact of the bank 5S5 which in turn causes energization of the motor magnet 52 and operation of the switch 5S to its ninth contact. When the switch 53 reaches its ninth contact relay 4? becomes energized and supplies negative potential to the normal contact of the bank 6S4 which in turn starts the cycle of operation of relays 68, 69 and motor magnet 66 which causes rotation of the code transmitting switch 6S.

Since relay 140 is now energized, its left-hand contacts permanently interrupt the circuit which, in the case of the operation of the equipment to indicate the position of units having two positions, was intermittently completed between the conductors 7 and '78 in accordance with the code. Accordingly the switch 6S will not now transmit a code in accordance with the position of the switch 555. Its bank 63-2, however, will complete the circuit for the code transmitting relay '73 through the right-hand contacts of relay 140 and the left-hand contacts of the relays in the group 140149 preceding the operated relay which, in the case assumed, is 145. cult of code transmitting relay '73 will be completed from the negative bus 8 through conductor 76, winding of relay 73, wiper and normal contact of the bank (SS-2, when the wiper thereof is in its normal position, and right-hand contacts of the relay 140. Similarly, when the wiper 6S2 is on its first contact this circuit will be completed through the left-hand contacts of relay 141 and right-hand contacts of relay 140. When it is on position 2 it will be completed through said contact and the left-hand contacts of relay 142, 141, and the right-hand contacts of relay 140. Similarly the code transmitting relay '73 will be energized when the switch (SS-2 occupies its 2nd, 3rd and fourth positions. In subsequent positions of the switch 6S-2 prior to its tenth contact the circuit of code transmitting relay 73 will be interrupted at the lefthand contacts of relay 145, such that in each of these positions the relay 73 will be deenergized and since relay 14 is now deenergized the circuit of the low pitch buzzer 13 will be completed on each or" the six contacts including contacts 5, 6, '7, 8, 9 and 10 of the switch 6S-2 thereby causing the buzzer to transmit six impulses of low pitch informing the operator that the unit 4 is in engagement with its sixth contact. Had unit 4 been in engagement with its eighth contact, relay 143 would have been energized and, accordingly, 8 low pitch impulses would have been transmitted. Similarly had it been on its second contact, relay 149 would have been energized and two low pitch impulses would have been transmitted to the remote station.

The operator having determined the position Thus the cirof the selected unit 4 may now change that position by dialing the additional code of three or five impulses. If three impulses are dialed relay 19 will operate to energize relay 4 with current of polarity such that the motor mechanism controlled thereby will operate the unit a in one direction, we will say to raise the load on a generator; and if five impulses be dialed relay 19 will respond to reverse the position of relay 4 thereby operating unit 4 in the opposite direction, thereby, as assumed, to lower the load. In this operation the relay 4 may operate as a master relay to control additional relays indi cated by the rectangle 4 for maintaining the energization of the motor during a suitable time interval.

It will be seen that the code transmitted will change directly in accordance with the different positions of the unit. Thus the operator may select a particular generator field rheostat, we will say, or water gate, and then by dialing the position changing codes change the position of the selected rheostat, or gate, back and forth as many times as desired without again operating the apparatus unit selecting equipment, the received code continuously furnishing a positive indication of the change, and extent of change, resulting from each position changing code.

The operator having determined the position of the selected unit and controlled it as desired may now reset the equipment as before by pressing the reset key. The energization of relay 4 during the resetting operation will cause the deenergization of relays 140 and 145.

The operator may now, by dialing the code 3-2-9, select and determine the position of the apparatus unit 5 by deenergizing relay 5" and subsequently control this unit in a manner which will now be understood.

When no units having more than two positions are to be supervised the relays 140 to 149 may be mitted the conductor '78 being connected to the positive bus as indicated at 78'.

While I have shown a particular embodiment of my invention, it will of course be understood that I do not wish to be limited thereto since many modifications, both in the circuit arrangement and in the instrumentalities employed, may be made, and I therefore contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

l. The combination, in a receiving control systerm, a plurality of apparatus units, each unit having a plurality of positions, a plurality of selectors including a transfer selector, an apparatus unit selector, and a position selector, said apparatus unit selector including a plurality of selector switches, each selector switch and said transfer selector having an operating magnet, means for supplying a plurality of groups of impulses in code combination to said system and for later supplying an additional group of impulses to said system, means including the transfer selector ior supplying each group of impulses of said code combination to an operating magnet of a different selector switch in said apparatus unit selector, whereby a particular apparatus unit is selected, and for connecting the operating magnet of said position selector to respond to said additional group of impulses, and means responsive to the position selector for controlling the position of the selected apparatus unit.

2. In combination, a plurality of devices, each of said devices being capable of assuming difierent positions, means common to all of said devices for transmitting a code of impulses of current corresponding to each device, remotely controlled selector mechanism for selecting a device for remote control, means controlled by said selector mechanism for causing said transmitting means to transmit a code of impulses of current corresponding to a selected device, without operating said device, means for controlling the character of current comprising the impulses or" said code in accordance with the position of the selected device, and means for causing said code of impulses to be transmitted in response to automatic operation or" said selected device.

3. In combination, a plurality of apparatus units, each of said units being operable to different positions, a normally energized relay associated with each unit, means responsive to the deenergization of any of said relays for repeatedly transmitting a code corresponding to the unit with which the deenergized relay is associated, means for causing deenergization of each of said relays in response to a change in position of the associated unit, and remote control means for eifecting the energization of the deenergized relay and for efiecting the termination of the transmisison of the code corresponding to the unit associated with the deenergized relay.

4. In combination, a plurality of apparatus units, each of said units being operable to different positions, a relay associated with each unit, a normally energized locking circuit for each relay, a code transmitter, means responsive to the deenergization of any of said relays for selectively causing said code transmitter repeatedly to transmit a code in accordance with the unit with which the deenergized relay is associated and for selectively preparing a resetting circuit for said relay, remote controlled means for selectively eliecting the deenergization of one of said relays to cause the transmission of the code corresponding to the unit with which it is associated and remote controlled means for eiiecting the completion of said resetting circuit after it has been prepared by said first mentioned means and for terminating the transmission of the code corresponding to the unit associated with the deenergized relay.

5. In combination, a plurality of apparatus units, each of said units being operable to different positions, a relay associated with each unit, position responsive means common to all of said units, a code transmitter, means responsive to operation of any of said relays for selectively causing said transmitter to transmit a code in accordance with the unit with which the operated relay is associated, for selectively preparing a reset circuit for said relay and for selectively connecting said position responsive means to the g;

unit with which said indicating relay is associated, means responsive to said position responsive means for characterizing the code transmitted in accordance with the position of said unit, and

means for controlling said relay and said reset 1] circuit from aremote point.

6. In combination, a plurality of apparatus units, each of said units being operable to a plurality of positions, a relay associated with each unit, means for selectively operating said relays from a remote point, means responsive to operation of each of said units for causing operation of the associated relay, means responsive to operation of any of said relays for transmitting a code corresponding to the unit with which the operated relay is associated and for selectively preparing a reset circuit to the operated relay, and means for controlling said reset cErcuit from a remote point thereby to reset said relay.

'7. In combination a plurality of apparatus units, each of said units being operable to a plu-- rality of positions, a relay associated with each unit, position responsive means common to all of said units, means responsive to operation of each unit for causing operation of the associated relay, remote control means for selectively operating said relays, means responsive to operation of any of said relays for transmitting a code in accordance with the unit with which the operated relay is associated and for selectively connecting said position responsive means to said unit, and means controlled by said position responsive means for characterizing the transmitted code in accordance with the position of the unit with which the operated relay is associated.

8. In combination, a plurality of apparatus units, a relay associated wlth each unit, a nor mally energized holding circuit for each relay, means for selectively completing a short circuit about any one of said relays to effect the deenergization thereof, means responsive to the deenergization of a relay for repeatedly transmitting an indication of the unit with which the deenergized relay is associated, and remote control means for effecting an interruption in said short circuit, the completion of an energizing circuit for the deenergized relay and the termination of the transmission or" the code corresponding to the unit associated with the deenergized relay.

9. In combination, a plurality of apparatus units, a relay associated with each unit arranged to be operated when the unit operates, a position responsive device, a code transmitter comprising a normally idle rotatable switching device having a wiper and cooperating bank of contacts, a selective swit mg device having a plurality of positions, means responsive to operation of any of said relays for operating said selective switching device to a predetermined position and for causingsaid code transmitter to rotate, connections selec tively prepared through said selective switching device in said position said connections including a reset circuit for said relay, a connection from the unit associated with the operated relay to said position responsive device and connections through said bank of contacts whereby a signal circuit is completed in accordance with code as said wiper rotates, said signal circuit including means for transmitting impulses in accordance with code determined by said switching devices, means controlled by said position responsive device to characterize the code in accordance with the position of the unit to which it is connected, and means including said reset circuit for restoring said relay to normal position.

10. In combination, a member operable through more than two positions, a relay associated with each position of said member, a code transmitter, remote control means for operating the relay associated with the position occupied by said memher, and for causing operation of said transmitter, and con actions controlled by the operated relay and said transmitter whereby a code cor esponding to the position of said member is trans" mitted.

11. In combination, in a selective supervisory system, a dispatchers station, a remote station, a plurality of apparatus units in the remote station, receiving equipment in the remote station including a plurality of receiving selectors, transmitting equipment including a transmitting selector, all of said selectors having a normal position and a plurality of other positions, means for operating all of said selectors from the normal position to one of said other positions dependent upon the unit selected, a key in the dispatchers station, and means responsive to openation of said key for restoring all of said selectors to normal position, a signal transmitter in the remote station and means for subsequently energizing said transmitter in response to operation of said key dependent upon all of said selectors occupying said normal position.

12. In a supervisory control system, a plurality of apparatus units, each unit being operable to different positions, a code selector common to said units and having a single position corresponding to each, unit, means for effecting the automatic operation of any unit from one of its positions to anotherof its positions, means responsive to an automatic operation of a unit for effecting the operation of said code selector to the position thereof corresponding to operated unit, remotely controlled selector mechanism for selecting an apparatus unit for remote controLineans controlled by said mechanism for effecting the operation of code selector to the position thereof corresponding to the unit selected by said mechanism, means controlled by said code selector while it is in a position corresponding to an apparatus unit for transmitting a code of current impulses individual thereto, and means for effecting the operation of a selected apparatus unit as many times as desired while said code selector remains in the position thereof corresponding to such selected apparatus unit.

13. In a supervisory control system, a plurality of apparatus units, each unit being operable to different positions, a code selector common to said units and having a single position corresponding to each unit, means for effecting the automatic operation of any unit from one of its positions to another of its positions, means responsive to an automatic operation of a unit for effecting the operation of said code selector to the position thereof corresponding to operated unit, remotely controlled selector mechani m for selecting an apparatus unit ior remote control, means controlled by said mechanism for eilecting the operation of said code selector to the position thereof corresponding to the unit selected by said mechanism, means controlled by said code selector while it is in a position co esponding to an apparatus unit for transmitting a code of current impulses individual thereto and indicative of the position thereof, and means for effecting the operation of a selected ap ratus unit as many times as desired while said code selector remains in the position thereof co responding to such selected apparatus unit.

14. In a supervisory control system, a plurality of apparatus units, each tnilt being operable to different positions, a code selector common to said units and having a single position corresponding to each unit, means for effecting the automatic operation of any unit from one of its positions to another of its positions, means responsive to an automatic operation of a unit for efiecting the operation of said code selector to the position thereof corresponding to operated unit, remotely controlled selector mechanic for solecting an apparatus unit for remote control, means controlled by said mechanism for effecting the operation of said code selector to the position thereof corresponding to the unit selected by said mechanism, means controlled by said code selector While it is in a position corresponding to an apparatus unit for transmitting a code of current impulses individual thereto, means for effecting from a remote point the operation of a sel cted unit as many times as desired to any of its positions While said code selector remains in the position thereof corresponding to the selected unit and means for controlling the character of the impulses of said code in accordance with the position or" the unit corresponding to the position of said code selector.

15. In a supervisory control system, a plurality of apparatus units, each unit being operable to different positions, a code selector common to said units and having a single position corresponding to each unit, means for efiecting the automatic operation of any unit from one of its positions to another of its positions, means responsive to an automatic operation of a unit for effecting the operation of said code selector to the position thereof corresponding to operated unit, remotely controlled selector mechanism for selecting an apparatus unit for remote control, means controlled by said mechanism for effecting the operation of said code selector to the position thereof corresponding to the unit selected by said mechanism, means controlled by said code selector While it is in a position corresponding' to an apparatus unit for transmitting a code of current impulses individual thereto, means for efiecting from a remote point the operation of a selected unit Without efiecting a change in the positions of said mechanism and said code selector and means for varying the character of the impulses of said code in response to a change in the position of the corresponding unit.

JAMES H. OLIVER. 

